I have a couple of faulty segments on the odometer display of my 1.8 NC, so that the mileage doesn’t show properly. I know I can’t just swap a new clock cluster in without having it reprogrammed.
I’ve bought a used instrument set from a breaker, and removed the LCD panel, as per piccy.
Does anyone know if there is any reason (coding/reprogramming issues maybe?) why just swapping and resoldering this panel into my existing instrument cluster won’t work? There is nothing hidden in the plastic assembly that might form part of the ID coding, other than the panel itself, so by re-using the existing cluster I’m hoping I’ll avoid any coding issues.
I can’t answer your question but I’d be interested to know the outcome of the swap. I would have guessed that the LCD unit also contained the microprocessor for the instrument cluster (it does on the NB) so swapping it would mean the unit would still need coding, but if it contains nothing more than the LCD itself it may work.
Robbie, I was wondering the same, but attached piccy of the LCD assembly shows it’s just the screen, the plastic mount, and a clip to hold it all together.
Haven’t actually seen this screen working, but am assured the cluster was fully functional by the breaker, and it came off an NC with only 19k miles.
Knowing my luck though there will be some annoying ‘feature’ that means this won’t work!
I’ve already realised two things though:-
1- Check the positions of the indicator needles relative to the spindle stops before removing them!
2- Be very careful desoldering because the pads are quite fragile if overheated.
Thanks, Robbie. The intention was to see if it was feasible and work out how to do it on this spare, considering I’d only lost it’s cost of £22 if it all went wrong.
Now it seems do-able I’ll have a go proper next week when I have a day or so to do it taking my time, and will report back how I get on.
I am of course making the assumption that it is the display itself that is faulty, and not the display driver IC, which would be a whole different ball game to replace! Would be really nice if it turned out to be just a couple of dry joints on the display connection!
Incidentally, does anyone know if this is a common fault?
Not more so on Mazdas than any other car for that kind of technology.
But it is possible.
The environment is hostile; wide temperature ranges, wide humidity ranges, possible high vibration. Any such device with glass/plastic and multiple connections between dissimilar materials tends to lose a few bits of connection with time.
After twenty years my Vextra-B display had lost maybe 5% of random dots. Out on the workbench, pressing on the display in certain places would restore it, but all the reports of attempted solder repairs by others suggested I could only make it worse! And replacement price at the time was silly money to spend on an old car, so I put it back ‘unrepaired’.
BEWARE
of attempting to solder any multilayer flexy-rigid printed circuit boards. Car and camera makers love them, as income generators.
Unless the board has been dehydrated overnight in an oven at about 80C, soldering can turn the absorbed moisture in the flexy film to steam, and this sudden expansion breaks internal connections (vias) between conductor layers. PCB is now totally U/S.
Been there, done that on a £350 prototype camera board - nobody warned us! Fortunately, we’d made three.
Pic of a CAD pre-layout trial-fit showing how the flexy inner layer allows it to fold up without any extra connectors between rigid boards.
Far too hot the couple of weeks immediately after posting for me to risk dripping salty sweat all over the electronics, and then have either been using the car so couldn’t risk leaving it in bits, or away.
Still intend to give it a go as soon as I can though👍🏻
Were you able to do this and did it work, just started using my 5 after being tucked away for the winter and the screen is unreadable, hoping it will improve a little with use of the car like it did last year.
Will need to do something soon as its going to be an issue MOT time.
Apologies for the delay replying Stewart, the email notification of your post ended up in my spam folder for some reason!
I haven’t done it yet, for a number of reasons. Not wanting to leave myself without transport if it took longer than expected, getting nervous that cold weather would make all the plastic brittle, deciding to wait for better weather etc etc.
I will say though that the odometer isn’t required to work for the MOT. Mine was done in January and they just put it down as ‘mileage not recorded’ or something like that. I have it recorded on the service sheet that was done at the same time though, so it is still traceable in one way if need be.
I will update progress when I do anything though, good or bad.
The LCD is just an LCD, unfortunately no markings of any sort that allows an easy search for a suitable replacement rather than going the second hand dash route.
Once both dash units were on the bench, it was just over an hour to do the work.
and then have either been using the car so couldn’t risk leaving it in bits, or away.
